1, pygmy marmoset: Found in the rainforests of South America, it is the smallest monkey in the world. An adult is only 16 cm long (not including the tail), which can be easily placed in the palm of your hand, while its tail is more than 30 cm long. This tail is different from other monkeys and is mainly used for balance. They are typically monogamous and stay together for life.
2. Dwarf Octopus: This octopus is the smallest octopus known in the world so far. The adult octopus weighs less than one gram and is only 1.5 cm long, which means that it can be comfortably attached to one of your fingers and distributed in the Indian Ocean and the Pacific Ocean.